Solid epoxy resins from glycidyl ethers of hydrogenated bisphenols or hydrogenated novolacs and aromatic or cycloaliphatic dicarboxylic acids

ABSTRACT

SOLID EPOXY RESINS ARE PREPARED FROM DIGLYCIDYL ETHERS OF A HYDROGENATED BISPHENOL OR HYDROGENATED NOVOLACS SUCH AS HYDROGENATED BISPHENOL A AND AN AROMATIC OR CYCLOALIPHATIC DICARBOXYLIC ACID SUCH AS ISOPHTHALIC ACID. THESE SOLIDS RESINS MAY BE COMMINUTRE INTO A STABLE FREEFLOWING POWDER USEFUL AS EPOXY RESIN POWDER COATINGS HAVING EXCELLENT WEATHERING PROPERTIES.

f 3,836,485 Ice Patented Sep 1974 3,836,485 The novel epoxy resins of the present invention are SOLID EPOXY RESINS FROM GLYCIDYL ETHER suitably represented by the general formulas F HYDROGENATED BISPHENOLS 0R HYDRO- GENATED NOVOLACS AND AROMATIC OR (I) R R CYCLOALIPHATIC DICARBOXYLIC ACIDS I Pong Sn Shih, Clute, Tex., assignor to The Dow 5 CHCHCH;O' s A 0 Chemical Company, Midland, Mich. No Drawing. Continuation-impart of abandoned application Ser. No. 229,181, Feb. 24, 1972. This application R R June 4, 1973, Ser. No. 366,390 I- OH 0 0 Int. CLC08g30/10 10 Us. (IMG 2131, 20 Claims Lem-21H CH1 0 c Q o CHI-(3H CH: 01

ABSTRACT OF THE DISCLOSURE R I R Solid epoxy resins are prepared from diglycidyl ethers 0 of a hydrogenated bisphenol or hydrogenated novolacs such as hydrogenated bisphenol A and an aromatic or C CH CH"O cycloaliphatic dicarboxylic acid such as isophthalic acid. '1

n R B These solid resins may be comminuted into a stable freeflowing powder useful as epoxy resin powder coatings Wherem A is a drvalent aliphatic hydrocarbon group having excellent weathering properties. having from 1 to 6 Carbon atoms,

0 0 g g This application is a continuation-in-part of my copending application Ser. No. 229,181, filed Feb. 24, 1972, and now abandoned. 25 Q is the organic residue of an aromatic dibasic acid, each This invention relates to epoxy resins and more par- R is independently hydrogen, an aliphatic hydrocarbon ticularly it relates to epoxy resins which are useful as group having 1 to about 6 carbon atoms, chlorine or bropowder coatings for outdoor service. mine, n has an average value such that the average Higher molecular weight epoxy resins suitable for EEW of the resin is at least about 700, preferably from powder coatings usually have a Durrans softening point about 1000 to about 1550 and x is zero or 1.

R n. 1 R itigant}. at: HP E831; L R Jm R i err-ca m.

l as...logtlgtlgsnzmui of from about 80 to about 120 C. and above and have wherein each R, Q and n are as defined in Formula I usually been prepared from glycidyl ethers of bisphenols and each R is independently hydrogen or an aliphatic and bisphenols. However, such resins possess poor weathhydrocarbon group having 1 to about 6 carbon atoms,

cring characteristics. 7 and each in has an average value of from about 0.01 to It has now been unexpectedly discovered that the epoxy about 0.6, preferably from about 0.01 to about 0.3.

resin compositions of the present invention have excellent The term free-flowing stable powder used herein means weathering characteristics and are suitable for use inepoxy that the epoxy resin when ground or otherwise compowder coating compositions. minuted into a free flowing powder will remain free flow- The novel epoxy resin compositions of the present ining for at least 48 hours.

vention comprises a solid product having a softening point The novel epoxy resin compositions of the present inabove about C. and preferably from about to vention are readily prepared by reacting a diglycidyl ether about C. and which can be comminuted to a freeof a hydrogenated bisphenol with an aromatic or cycloflowing stable powder which result from the a tio of aliphatic dibasic acid at a temperature of from about 80 a diglycidyl ether of a hydrogenated bisphenol or hydroto about 210 C. in the presence of a suitable catalyst genated novolac having an average functionality of from 65 Such as tertiary amines, quaternary ammonium about 2.01 to about 2.6, preferably from about 2.01 to P quaternary Phosphonium Compounds, of the like,

about 2.3, and an aromatic orcycloaliphatic dibasic acid for a time Sufficient to Produce the Product, Usually from wherein the quantities of the glycidyl ether and the diabout 0.5 to about 30 hours. It is usually desirable, parbasic acid is such as to provide an epoxyzCOOH ratio ticularly when laboratory apparatus is employed, to preof from about 1.1 :1 to about 2.0: 1, preferably from about 70 blend all of the reactants and then add the catalyst thereto. 1.1:1 to about 1.821, and most preferably from about Suitable catalysts include, for example, quaternary aml.3:1 to about 1.5 :1. monium compounds such as benzyl trimethyl ammonium chloride, amines such as N-methylmorpholine and phosphonium compounds such as those compounds disclosed in US. Pat. No. 3,477,990 and Canadian Pat. No. 893,191.

Suitable glycidyl ethers of a hydrogenated bisphenol include the glycidyl ethers of such hydrogenated bisphenols as, for example, hydrogenated p,p-isopropylidine-diphenol, hydrogenated p,p-methylenediphenol, hydrogenated dihydroxydiphenyl sulfone, hydrogenated 4,4'-dihydroxy biphenyl, hydrogenated 4,4'-dihydroxydiphenyl oxide, mixtures thereof and the like.

Suitable aromatic carboxylic dibasic acids include, for example, phthalic acid, terephthalic acid, isophthalic acid, and those acids represented by the formula (III).

(III) HOOC Z COOH wherein Z is independently selected from the same group as A in Formula I, such as, for example, 4,4'-diphenylsulfide dicarboxylic acid, 4,4'-diphenyldisulfide dicarboxylic acid, 2,5-furan dicarboxylic acid and mixtures thereof.

Suitable cycloaliphatic dibasic acids include, for example, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexyltetrahydrophthalic acid, dimethylhexahydrophthalic acid, hexylhexahydrophthalic acid, bromotetrahydrophthalic acid, chlorotetrahydroisophthalic acid, chlorendic acid, methyltetrahydroterephthalic acid, mixtures thereof and the like.

The novel epoxy resin compositions of the present invention may becured to a thermoset product by any of the well known catalysts or curing agents such as primary, secondary and tertiary amines, amides, acid anhydrides and the like.

The quantities of curing agent or catalysts employed depends upon the particular catalyst or curing agent employed and the particular catalyst or curing agent depends upon the properties desired as those skilled in the epoxy resin art are readily aware. Those not so skilled in this art but who desire to make use of thi invention are directed to the Handbook of Epoxy Resins, Lee and Neville, McGraw-Hill Book Co., 1967.

Although the novel epoxy resins of the present invention are particularly useful in epoxy resin powder coating formulations they may also be employed in molding compositions, admixed with suitable solvents for use in solution coatings, castings, potting compounds, ad hesives and the like.

The following examples are illustrative of the present invention but are not to be construed as to limiting the scope thereof in any manner.

EXAMPLE 1 To a reaction vessel equipped with a means for temperature control, stirring and nitrogen purging were added 600 grams of the diglycidyl ether of hydrogenated bisphenol A having an epoxide equivalent weight of 212 and 170 grams of isophthalic acid. After heating to a temperature of 150 C., 0.9 grams of ethyltriphenyl phosphonium acetate-acetic acid complex catalyst was added and the temperature maintained at 150 C. by cooling or heating as required for about 5 hours. The resultant epoxy resin had an average epoxide equivalent weight (EEW) of 1200 and a Durrans softening point of 95 C.

Powder coatings were then prepared from the above resin designated as resin A employing the following compositions designated as Formulations A and B by blending components (1), (7), (8) and (9) on a two roll mill for about 10 minutes. Then components (3) and (4) or (5) and (6) as indicated were blended with the previous blend on the two roll mill for about 3 minutes. The above blend was then ground to a fine free-flowing powder on a hammermill. Then the powder was screened through a 200 mesh US. Standard Sieve Series screen.

Formulation Component (1) Resin A, rms (2) D.E.R. 664, gms (3) Triinellitic anhydride, gms

(4) Stannous octoate, accelerator, gms 3. 0 3. 0 5.1..- (5) Dicyandiamide, gms 4. 5 6. 4 (G) 82% dicyandiamide, 17% Z-meth limid azole and 1% Cah-O-Sil (by wt gms 4. 5 6. 4 (7) TiOz pigment, grns- 225 225 225 (S) Aerosil gms 9.0 (9) Modnilow Y 4.5 4.5 4.5

1 Aerosil is a high surface area subrnicroscopic pyrogenic silica com mercially available from Degussa, no.

3 Modafiow is a flow control agent commercially available from Monsanto Co.

Each of the above formulations were electrostatically sprayed onto #5412 Steel Q panels and cured at 200- C. for 7 minutes for Formulations A, C and D and 15 minutes for Formulation B, and then a portion of the panels were placed in a Fade-O-Meter and the remaining panels were placed in a Weather-O-Meter to obtain weathering properties of the coatings. These tests were conducted according to ASTM D822 and ASTM' The results were as follows:

Fade-O-Meter", percent Weather-O-Meter",

gloss retention percent gloss retention 140 300 500 800 100 300 400 1,000 Formulation hrs. hrs. hrs. hrs. hrs. hrs. hrs. hrs.

A 100 90 92 90 64 58 N.D. B 100 100 100 92 76 76 69 c. 32/y 7/yc N.D. N.D. s1 15/y l3/y N.D. D 55/y 17/yc 13/yc N.D. 69 32/y 14/y 14/yc l y=yellowing oi the surface. yc=yellowing and chalking of the surface. 3 N.D.=not determined.

EXAMPLE 2 A solution coating was prepared by blending the following components.

The coating was applied to a Q panel and cured at C. for about 6 hour. The coated panel was placed in a Weather-O-Meter and the following results obtained.

Hours of Exposure: Percent gloss retention 73 as 216 9'2 547 a 87 EXAMPLE 3 A molding composition was prepared from resin A prepared in Example 1 by blending the following components.

50 grams of Resin A 5.0 grams of trimellitic anhydride Resin A was ground to a coarse powder and admixed with the curing agent on a roll mill. The mixture was placed into a preheated mold and cured at "177 C. at

6 1000 p.s.i.g. for 30 sec. and then postcured at atmospheric 2. An epoxy resin of Claim 1 represented by Formula I pressure and 177 C. for about 30 minutes. wherein Q is the residue of an aromatic acid.

The resultant casting was placed in a Weather-O-Meter 3. An epoxy resin of Claim 2 wherein at has a value and after various periods of exposure, the casting was of 1. evaluated by an Arc Resistant Test, ASTM D-495. The 5 4. An epoxy resin of Claim 3 wherein A is an isoprorcsults were as indicated belowpylidene group and Q is the residue of isophthalic acid. Time in W6ather O Meter Arc resistance 5. Ancpoxy resin of Claim 1 represented by Formula hrs: sec II wherein R' 18 hydrogen and m has an average value of Initial from about 0.01 toabout 331 85 10 6. An epoxy resin of Claim 5 wherein each R is hydro- 706 85 gen and Q is the residue of an aromatic dibasic acid.

7. A thermosettable composition comprising an epoxy I claim: resin of Claim 1 and a catalytic amount of a curing cata- 1. An epoxy resin having a Durrans softening point of lyst or a curing amount of a curing agent. from at least 80 C. to about 120C. and which can be 8. A thermosettable composition comprising an epoxy comminuted into a free flowing stable powder represented resin of Claim 2 and a catalytic amount of a curing cataby the general formulas lyst and a curing amount of a curing agent.

wherein A is a divalent aliphatic hydrocarbon group having from 1 to about 6 carbon atoms,

9. A thermosettable composition comprising an epoxy resin of Claim 3 and a catalytic amount of a curing catalyst and a curing amount of a curing agent.

h, or -0-, 10. A thermosettable composition comprising an epoxy resin of Claim 4 and a catalytic amount of a curing catalyst and a curing amount of a curing agent. Q is the residue of a dibasic aromatic or cycloaliphatic 11. A thermosettable composition comprising an epoxy carboxylic acid which would result from the removal of resin of Claim 5 and a catalytic amount of a curing catathe carbonyl groups, each R is independently hydrogen, an lyst and a curing amount of a curing agent. aliphatic hydrocarbon group having from 1 to about 6 12. A thermosettable composition comprising an epoxy carbon atoms, chlorine or bromine, n is an integer such resin of Claim 6 and a catalytic amount of a curing catathat the average EEW of the resin is at least about 700 lyst and a curing amount of a curing agent. and x has a value of zero or 1, and

CHQCH:

O Era-on on.

R R R O\ R OH O O CCHCHr-O CH 43H S O-CHz-JJH-CHs-O-QD-Q- n i R L B Jim R wherein each R, Q and n are as defined in Formula I and 13. The thermosettable composition of Claim 10 whereeach R is independently hydrogen, or an aliphatic hydroin said curing agent is an amide. carbon group having 1 to about 6 carbon atoms, and each 14. The thermosettable composition of Claim 13 wherein has an average value of from about 0.01 to about 0.6. in said curing agent is dicyandiamide.

17. An article coated with the composition of Claim 8. 5

18. An article coated with the composition of Claim 9. 19. An article coated with the composition of Claim 10. 20. An article coated with the composition of Claim 11.

References Cited UNITED STATES PATENTS 2/ 1969 Jellinek et a1 260-2 2/1970 Christenson et a1. 260-834 FOR IGN PTENTS 1,094,138 12/1967 Great Britaini', OTHER REFERENCES Abstract of Netherlands application 6609397;published Jan. 11, 1967, Chem. Abstr. 67, 22429g (1967 10 WILLIAM H. SHORT, Primary Exa niiheif.

E. A. NIELSEN, Assistant Examiner H 117-21; 260-2 EC, 2 EA, 2 N, 37 EP,"59,' 78.4 EP 

